1. Field of the Invention
The present invention relates generally to hydraulic water pumps and more specifically to a method of removing a sensing rod from a hydraulic water pump without disassembling thereof.
2. Discussion of the Prior Art
Hydraulic water pumps are commonly used to pump water for pipeline cleaning. The hydraulic water pump utilizes a sensing rod to make contact with a roller arm or to trigger a proximity switch. Actuation of the roller arm or activation of the proximity switch causes a solenoid operated hydraulic valve to open the flow of hydraulic oil to one port and close the other port. Unfortunately, the sensing rod is exposed to the outer atmosphere. The sensing rod will become damaged from weather exposure and physical abuse. If the sensing rod becomes damaged, a rod seal will not be able to seal the sensing rod and hydraulic fluid will leak out of the hydraulic water pump. Leakage of hydraulic fluid is unacceptable and the sensing rod must be replaced. However, it takes approximately 10-12 hours to replace the sensing rod, because the hydraulic water pump must be removed from a truck and thereof must also be disassembled. Unfortunately, removing an end plate results in the entire pump becoming disassembled.
Accordingly, there is a clearly felt need in the art for a method of removing a sensing rod from a hydraulic water pump without disassembling thereof.
The present invention provides a method of removing a sensing rod from a hydraulic water pump for ease of maintenance. The method of removing a sensing rod from a hydraulic water pump includes an access plug, a sealing o-ring, and an end block modified to receive the access plug. The access plug is preferably retained in the modified end block by forming external threads on the access plug, which mate with internal threads formed in the modified end block, but other retention methods may also be used such as retaining the access plug with a snap ring.
The access plug preferably includes a front flange, a threaded body, and a rear tapered end. An o-ring groove is formed adjacent the front flange to retain the sealing o-ring. A rod opening is formed through the length of the access plug which is sized to receive the sensing rod. A flange bore is formed on a front of the modified end block to receive the front flange of the access plug.
The sealing o-ring is inserted into the o-ring groove, before the access plug is threaded into the modified end block. The sealing o-ring prevents oil from leaking from around the outer perimeter of the access plug. When maintenance needs to be performed on the sensing rod, the access plug is unscrewed from the modified end block. A nut removal tool is inserted through the internal threads in the modified end block to unscrew a rod nut. Once the rod nut has been unscrewed, the sensing rod is removed. The hydraulic water pump does not have to be disassembled to replace the sensing rod. Replacement of the sensing rod using the method of removing a sensing rod from a hydraulic water pump takes approximately one hour.
Accordingly, it is an object of the present invention to provide an access plug for a hydraulic water pump which allows maintenance to be performed on a sensing rod without disassembling the entire hydraulic water pump.
These and additional objects, advantages, features and benefits of the present invention will become apparent from the following specification.